Vector-like quarks in a composite Higgs model

TL;DR

This paper analyzes a specific SO(5)/SO(4) composite Higgs model with vector-like quarks, showing that some configurations allow quarks as light as 300-500 GeV while remaining consistent with electroweak precision tests.

Contribution

It provides a detailed analysis of a non-minimal SO(5)/SO(4) composite Higgs model, identifying parameter space where light vector-like quarks are compatible with EWPT.

Findings

Light vector-like quarks (300-500 GeV) are possible in a specific non-minimal model.

Most models analyzed are inconsistent with electroweak precision tests.

The model constrains the parameter space for vector-like quark masses.

Abstract

Vector-like quarks are a common feature of "composite" Higgs models, where they intervene in cutting off the top-loop contribution to the Higgs boson mass and may, at the same time, affect the Electroweak Precision Tests (EWPT). A model based on SO(5)/SO(4) is here analyzed. In a specific non minimal version, vector-like quarks of mass as low as 300-500 GeV are allowed in a thin region of its parameter space. Other models fail to be consistent with the EWPT.